/*
    二叉树
 */
public class test16 {
    public static void main(String[] args) {
        int t = 1;
        int sum = 0;
        for (int i = 1 ; i <=10 ; i++){
            if (i==1){
                t=1;
            } else {
                t *=2;
            }
            sum += t;
        }
        System.out.println(sum);
    }
}
